Each electronic device typically includes a chip—for example, of semiconductor material, on which on one or more electronic components are integrated, and a package wherein the chip is encapsulated for protecting it and for allowing access to terminals thereof.
In this respect, the package typically includes an insulating body having exposed leads, each one of which is electrically connected to a corresponding terminal of the chip (for example, through a wire-bonding technique). The package leads are used for connecting the package (and hence the corresponding terminals of the chip) to external circuits. For such purpose, the electronic device is usually mounted on a printed circuit board (PCB), for example, by surface mounting technology (SMT), wherein the package leads include pads that are first fixed to corresponding conductive tracks of the PCB by means of a slight pressure (pick and place), and then reflowed on the same, or by through-hole technology (THT), wherein the package leads include reophores that are inserted into through holes of the PCB and back-welded on it.
As should be known, considerable design efforts are aimed at making more and more compact electronic devices.
In this respect, although advanced integration techniques currently exist that allow achieving a remarkable reduction in the size of the chip, the reduction of the overall size of the corresponding electronic device may still be not significant.
This may occur, for example, when the size of the electronic devices mainly depend on the size of the respective package, as in case of electronic device for power applications (e.g., motor and power suppliers control), or power device, which includes one or more power components integrated on the chip.
For example, a very common class of power components is represented by vertical structure MOS power transistors; the latter, being affected by high voltages (such as 5.5 V-850V), are subject to considerable heating during operation thereof. For this reason, the chip on which the power component is integrated needs a package that, in order to ensure adequate heat dissipation properties (so as to avoid overheating phenomena to the chip that may cause malfunctioning or breakages), is provided with one or more heat-sinks for dissipating the heat generated by the chip during operation thereof to the outside.
An example of such a package is the DSC (“Dual Side Cool”) package, which is provided with two separate heat-sinks In particular, each power device having a DSC package (or DSC power device) includes a heat-sink extending between a conductive region of the chip (e.g., a drain terminal of the power transistor) and a mounting surface of the insulating body facing the PCB, and a further heat-sink extending between another conductive region of the chip (e.g., a source terminal of the power transistor) and a free surface of the insulating body (typically opposite the mounting surface).
As should be known, an increasing number of applications require that the DSC power devices have very small size (e.g., thickness lower than 1 mm, which we will be referred to as sub-millimeter thickness); however, since shape and/or size of heat-sinks, leads, insulating body and terminals should comply with specific safety parameters of the DSC power device (for example, air distances—creepage distances—and/or surface distances—clearance distances), a reduction in the thickness of the DSC power device would imply such structural changes to require an at least partial redesign of the same. Since this would imply timing and/or costs often not compatible with market requirements, currently there are no sub-millimeter thickness DSC power devices being commercially available.
Furthermore, as should be known, a chip may integrate one or more high power components within it (i.e., able to withstand operating voltages higher than 300V, and up to 850V), so that it is more subject to overheating. For this reason, a chip of this kind needs to be encapsulated within a DSC package having better dissipation capacity (e.g., by using heat-sinks having a larger dissipation surface).
However, an increase of the dissipation surface of the heat-sinks, in addition to impact safety parameters (with the same problems described above), would involve a larger encumbrance of the corresponding DSC device. For the described reasons, there are no high-power DSC devices with limited encumbrance being commercially available.